Expanding interbody implant and articulating inserter and method

ABSTRACT

A device to space vertebral members with first and second members that may have at least one ramped section. The first and second members may be positioned in a vertically overlapping arrangement with interior sides of the members facing together. The device may be positionable between a first orientation with the ramped section of the first member positioned away from the ramped section of the second member, and a second orientation with the ramped section of the first member positioned against the ramped section of the second member. The device may include a greater height measured between the exterior sides in the second orientation than in the first orientation.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/763,115, filed on Jan. 22, 2004, and claims priority to U.S.provisional application Ser. No. 60/444,561, filed on Feb. 3, 2003.These applications are expressly incorporated in their entirety hereinby reference.

BACKGROUND

Various devices are used for controlling the spacing between vertebralmembers. These devices may be used on a temporary basis, such as duringsurgery when it is necessary to access the specific surfaces of thevertebral member. One example includes preparing the endplates of avertebral member. The devices may also remain permanently within thepatient to space the vertebral members.

It is often difficult to position the device between the vertebralmembers in a minimally invasive manner. A device that is small may beinserted into the patient and between the vertebral members in aminimally invasive manner. However, the small size may not be adequateto effectively space the vertebral members. A larger device may beeffective to space the vertebral members, but cannot be inserted intothe patient and between the vertebral members in a minimally invasivemanner.

SUMMARY

The present application is directed to devices to space vertebralmembers. One device may include first and second elongated, non-annularmembers each with opposing first and second ends, an exterior side, andan opposing interior side with at least one ramped section. The firstmember may further include a sidewall on the interior side positionedcloser to a perimeter of the first member than the ramped section. Thesidewall may have a height greater than the ramped section to extendoutward from the interior side beyond the ramped section. The first andsecond members may be positioned in a vertically overlapping arrangementwith the interior sides facing together and the sidewall in ahorizontally overlapping arrangement with second member. The device maybe positionable between a first orientation with the ramped section ofthe first member positioned away from the ramped section of the secondmember, and a second orientation with the ramped section of the firstmember positioned against the ramped section of the second member. Thedevice may include a greater height measured between the exterior sidesin the second orientation than in the first orientation.

A device may also include a base member, a first ramped member with afirst side that abuts against the base member and an opposing secondside that includes a first ramped section, and a second ramped memberwith a first side having a second ramped section that faces towards thefirst ramped member and an opposing second side that may face away fromthe base member. The base member and first and second ramped members maybe in a vertically overlapping arrangement. The base member may be in ahorizontally overlapping arrangement with the first ramped member. Thefirst ramped member may be configured to move laterally relative to thebase member between a first orientation with the first and second rampedsections positioned apart and a second orientation with the first andsecond ramped sections positioned in contact. The second ramped membermay be operatively connected to the base member to move vertically awayfrom the base member while being constrained from moving horizontallywhen the first ramped member moves from the first orientation to thesecond orientation.

A device may also include a base member, a first ramped member includinga first side that abuts against the base member and an opposing secondside that includes first and second ramped sections, and a second rampedmember including a first side with third and fourth ramped sections thatare aligned towards the first ramped member. The second ramped membermay further include an opposing second side that faces away from thebase member. The device may have a longitudinal axis that extendsthrough opposing first and second ends of each of the base member andfirst and second ramped members. The longitudinal axis may furtherextend through each of the first, second, third, and fourth rampedsections. The first ramped member may be configured to move along thelongitudinal axis relative to the base member and the second rampedmember between a first orientation with the first and third rampedsections positioned apart, and the second and fourth ramped sectionspositioned apart, and a second orientation with the first and thirdramped sections abutting together and the second and fourth rampedsections abutting together. The second ramped member may be operativelyconnected to the base member to move vertically away from the basemember and may be constrained from moving along the longitudinal axiswhen the first ramped member moves from the first orientation to thesecond orientation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the present invention;

FIG. 2 is a perspective view of the spacer in a closed orientationaccording to one embodiment of the present invention;

FIG. 3 is a perspective view of the spacer in an open orientationaccording to one embodiment of the present invention;

FIG. 4 is an exploded perspective view of the spacer according to oneembodiment of the present invention;

FIG. 5 is a perspective view of the first member according to oneembodiment of the present invention;

FIG. 6 is a perspective view of the third member in a first positionwithin the second member according to one embodiment of the presentinvention;

FIG. 7 is a perspective view of the third member in a second positionwithin the second member according to one embodiment of the presentinvention;

FIG. 8 is a partial cut-away perspective view of the locking mechanismaccording to one embodiment of the present invention;

FIG. 9 is a perspective view of the first member in contact with thesecond member according to one embodiment of the present invention;

FIG. 10 is a partial perspective view of the spacer angled relative tothe delivery device according to one embodiment of the presentinvention;

FIG. 11 is a partial perspective view of another embodiment of thespacer angled relative to the delivery device according to oneembodiment of the present invention;

FIG. 12 is a partial perspective view of the spacer disengaged from thedelivery device according to one embodiment of the present invention;

FIG. 13 is a partial perspective view of the holder and pivots in afirst orientation according to one embodiment of the present invention;

FIG. 14 is a partial perspective view of the holder and pivots in asecond orientation according to one embodiment of the present invention;

FIG. 15 is a partial perspective view of another embodiment of thespacer angled relative to the delivery device according to oneembodiment of the present invention;

FIG. 16 is a perspective view of the present invention according to oneembodiment of the present invention;

FIG. 17 is a partial perspective view of a section of the deviceaccording to one embodiment of the present invention;

FIG. 18 is a partial perspective view illustrating the third member in afirst position within the second member according to one embodiment ofthe present invention;

FIG. 19 is a partial perspective view illustrating the third member in asecond position within the second member according to one embodiment ofthe present invention;

FIG. 20 is a partial perspective view of a lock according to oneembodiment of the present invention;

FIG. 21 is a partial perspective view of live pivots according to oneembodiment of the present invention;

FIG. 22 is a perspective view of another embodiment of the third memberconstructed according to one embodiment of the present invention;

FIG. 23 is a partial perspective view of the cam in contact with thethird member constructed according to one embodiment of the presentinvention;

FIG. 24 is a partial perspective view of another delivery device andrelease mechanism constructed according to one embodiment of the presentinvention;

FIG. 25 is a partial perspective view of the spacer attached to thedelivery device constructed according to one embodiment of the presentinvention;

FIG. 26 is a partial perspective view of the tube sleeve and camconstructed according to one embodiment of the present invention;

FIG. 27 is a partial perspective view of the spacer attached to thedelivery device constructed according to one embodiment of the presentinvention; and

FIG. 28 is a partial perspective view of the spacer detached from thedelivery device constructed according to one embodiment of the presentinvention.

DETAILED DESCRIPTION

The present invention is directed to a device for positioning betweenadjacent vertebral members. FIG. 1 illustrates one embodiment, generallyindicated as 9, which includes a spacer 10, delivery device 80, and adeployer 7. Spacer 10 is positioned between adjacent vertebral membersand is selectively adjustable between a closed orientation, openorientation, and gradations therebetween. Delivery device 80 functionsto position the spacer within the patient. Deployer 7 moves the spacerto the selected expanded orientations.

Spacer 10 has a variety of shapes and sizes depending upon theapplication, such as an elongated, curved shape. The spacer 10 isadjustable between a first position as illustrated in FIG. 2 having areduced size to be minimally invasive when inserted into the patientbetween the vertebral members. FIG. 3 illustrates a second position withthe spacer 10 expanded to contact the vertebral members. The spacer 10may be expandable to a variety of different heights depending upon thedesired application.

FIGS. 2 and 3 illustrate one embodiment of the spacer 10 having arounded kidney shape with a first distal end 11 and second proximal end12 each having a rounded shape. First and second sides 13, 14 arecurved. The spacer 10 may have a substantially constant width, with onespecific embodiment having a width of about 33 mm The height of thespacer 10 may vary depending upon the amount of deployment and isdictated by the angle of the ramped surfaces as will be described indetail below. In one specific embodiment, spacer 10 has a height rangingfrom about 9 mm to about 13 mm In one embodiment, the spacer 10 isangled in one or more of the closed, open, or deploying orientations toconform to the dimensions of the vertebral member.

FIG. 4 illustrates one embodiment of the spacer 10 including a firstmember 20, a second member 30, and a third member 40. First member 20includes contact surface 21 and second member 30 includes contactsurface 31 each for contacting a vertebral member. Contact surfaces 21,31 may be substantially smooth, or may have stabilization features suchas ridges or knurls to contact the vertebral members.

First and second members 20, 30 have complementary shapes to matetogether in the closed orientation. Outward edges 22, 32 of the members20, 30 are adjacently positioned in the closed orientation to reduce theoverall size of the spacer 10. Outward edge 32 may contact or be spacedapart from the inner edge of the contact surface 21 when the spacer 10is in the closed orientation. Sidewalls 23, 33 extend from the contactsurfaces and may have a variety of different shapes and sizes to definethe overall shape of the spacer 10.

FIG. 5 illustrates one embodiment of the underside of the first member20. Sidewalls 23 extend outward to mate with the second member 30. A tab29 may extend outward from one of the sidewalls 23 to mate with a groovein the second member sidewall 33 to further stabilize during deploymentand when the spacer 10 is in the open orientations. Tabs 29 contact anupper edge of the groove (see FIG. 18) to prevent the first member 20from separating from the second member 30 during deployment of thespacer 10.

First member 20 includes a first angled section 25 and a support section27, and a second angled section 26 and support section 28. Angledsections 25, 26 may have a variety of lengths, and may be positioned ata variety of angles relative to the contact surface 21. The angledsections 26, 25 may be at the same angle, or may have different angles.In one embodiment, the range of angles between the sections 25, 26 andcontact surface 21 is between about 20° to about 40°. Support sections27, 28 are positioned adjacent to the angled sections 25, 26 and arepositioned at a different angle relative to the angled sections 25, 26.In one embodiment, support sections 27, 28 are substantially parallelwith the contact surface 21.

The shape of the second member 30 complements the first member 20.Sidewalls 33 extend around a portion or the entirety of the secondmember 30 to align with the first member 20 and form an interior sectionto maintain the third member 40. An inner section 39 is formed withinthe sidewalls 33 opposite the contact surface 31. In one embodiment asillustrated in FIGS. 7 and 8, inner section 39 is substantially flat andsmooth to facilitate the relative movement of the third member 40. Aframe 93 may extend from the second member 30. Apertures 37 positionedon the frame 93 allow for attachment of the delivery device 80 asexplained below.

Third member 40 is positioned between the first member 20 and secondmember 30. Third member 40 includes a first side 41 having angledsections 45, 46 that mate with the first member 20, and a second side 42to contact the second member 30. One embodiment of the first side 41 isillustrated in FIG. 4 and includes a first angled section 45 andadjacent support section 47, and a second angled section 46 and supportsection 48. Angled sections 45, 46 may have a variety of lengths, andmay be positioned at a variety of angles relative to the second side 42.In one embodiment, the range of angles between sections 45, 46 andsecond side 41 is between about 20° to about 40°. Support sections 47,48 are positioned at a different angle relative to the angled sections45, 46. In one embodiment, support sections 47, 48 are substantiallyparallel with the second side 42. In one embodiment, second side 42 isflat which complements a flat surface of the inner section 39.

Third member 40 may have a width and length less than or equal to theboundary formed by the sidewalls 33 of the second member 30. The smallersize provides for sliding movement of the third member 40 relative tothe second member 30. The relative positioning of the second and thirdmembers 30, 40 is illustrated in FIGS. 6 and 7. FIG. 6 illustrates afirst position with the third member 40 positioned against a proximaledge of the second member 30. FIG. 7 illustrates a second position withthe third member 40 positioned against a distal edge of the secondmember 30.

Third member 40 moves relative to the first and second members 20, 30 todeploy the spacer 10 from the closed orientation to the openorientation. The spacer 10 may be positioned within the patient in theclosed orientation that has a minimal size and shape to facilitateplacement within the patient and between the vertebral members. Theangled sections 25, 26, 45, 46 of the first and third members 20, 40 aredisengaged in the closed orientation.

Deployment of the spacer 10 is caused by the third member 40 movingrelative to the first member 20. Relative movement causes the angledsections 45, 46 of the third member 40 to contact the angled sections25, 26 of the first member 20. This causes the first member 20 to moveoutward away from the centerline of the spacer 10. As the third member40 is moved further, the angled sections continue to slide relative toone another and the first member 20 continues to move outward from thecenterline increasing the overall height of the spacer 10.

FIG. 9 illustrates one embodiment at the open position with fulldeployment. The sections 27, 28 on the first member 20 contact and reston sections 47, 48 of the third member 40. In one embodiment, thesections 27, 28, 47, 48 are angled to a lesser amount than the angledsections 25, 26, 45, 46 to prevent the spacer 10 from moving towards theclosed orientation. The angled sections 25, 26, 45, 46 may have the sameangle.

The rounded shape of the spacer 10 results in the some or all of theangled sections of the first and third members 20, 40 havingnon-symmetrical shapes. In one embodiment illustrated in FIG. 5, angledsections 25, 26 have a shorter length on the first edge 13 than on thesecond edge 14. Likewise, the angled sections 25, 26 are not alignedbecause of the rounded shape of the second member 20. FIG. 6 illustratesthat angled surfaces 45, 46 having a first inner edge shorter than thesecond outer edge, and the angled surfaces not being aligned.

The slope and sizes of the angled surfaces 25, 26, 45, 46 of the firstand third members 20, 40 may vary to change the shape of the spacer 10in the open orientation. The contact surfaces 21 and 31 may be obliquewith the one end of the spacer 10 having a larger height than the otherend, or may be substantially parallel in the open orientation andgradations of being open. The spacer 10 in the open orientation may beshaped to conform to the curvature of the spine.

In one embodiment, the spacer 10 includes two members each having angledsections and there is no third member. The angled sections of the firstmember contact the angled sections of the second member during thedeployment. Each of the members may further include platform sectionsfor contact in the open orientation.

The spacer 10 may expand in both a first and second direction. The thirdmember 40 includes angled sections on the second side 42 that contactangled sections on the inner section 39 of the second member 30. In oneembodiment, movement of the third member 40 results in both the firstmember 20 and second member 30 moving outward from a centerline of thespacer 10.

Another embodiment features one or more of the angled sections 25, 26,45, 46 having a stepped configuration. The stepped configurationfeatures an angled section having one or more steps positionedthereabout angled to a different degree. The steps are positioned alongthe angled sections 25, 26, 45, 46 for deploying the spacer 10 todiffering extents. A variety of step surfaces may be positioned on thesections. In one embodiment, angled sections 25, 26, 45, 46 each includetwo steps with the spacer positionable between a closed orientation,first orientation on a first step, second orientation on a second step,and fully deployed orientation.

The first member 20 and the second member 30 may also each include asingle angled section. Movement of the spacer 10 results in only thesingle angled surfaces contacting. The angled surfaces may be positionedat any point along the length of the spacer 10. In one embodiment,support surfaces are positioned adjacent to the angled surfaces.

A locking member 100 may lock the spacer 10 in a particular position. Inone embodiment as illustrated in FIG. 8, locking member 100 includes apair of caps 102 forced apart by a biasing member 108 (FIG. 8 featuresthe third member 40 removed for clarity). Each cap 102 includes anextension 106 sized to fit within the apertures positioned within thefirst member 20 or second member 30. In one embodiment, a pair ofapertures 35 are positioned on the third member 30 for receiving thelocking member 100. As the third member 40 moves relative to the secondmember 20, the locking member 100 extends into one or more of theapertures 35. In one embodiment, apertures are positioned for receivingthe caps 102 when the spacer 100 is at the open orientation and thesupport sections are in contact. In another embodiment, apertures 35 arepositioned for receiving the caps 102 while the angled surfaces are incontact. The locking member 100 prevents the third member 40 fromsliding outward and inadvertently reducing the spacer size. In a spacer10 having a stepped configuration on the angled sections, aperture pairsmay be positioned to lock the spacer at each gradation. In oneembodiment, locking mechanism 100 includes a single cap 102 that is fitinto a single aperture. A spacer is disclosed in previously filed U.S.patent application Ser. No. 10/229,560 entitled Minimally InvasiveExpanding Spacer and Method, filed Aug. 28, 2002 and assigned to thesame entity as the present application and herein incorporated byreference in its entirety.

The delivery device 80 functions to position the spacer 10 within thepatient. Delivery device 80 has an elongated shape for the physician toposition the spacer 10 within the patient between vertebral members. Inone embodiment as illustrated in FIG. 12, delivery device 80 has anelongated shape sized with a distal end attached to the spacer 10 and aproximal end positioned exterior to the patient. Delivery device 80 mayhave a variety of cross-sectional shapes and sizes depending upon theapplication. Delivery device 80 may be constructed of a single elongatedmember, or may be constructed of different sections.

Delivery device 80 may be mounted to the spacer in a pivoting manner.FIG. 11 illustrates one embodiment of the delivery device 80 comprisinga first shaft 81 and a second shaft 82. A holder 55 is positioned at thedistal end of the shaft 82. Holder 55 includes apertures 57 throughwhich live pivots 90 extend. In one embodiment, an angled edge 91conforms with the spacer frame 93. A link 54 is pivotally mountedbetween holder 55 and the first shaft 81. The first shaft 81 isselectively positionable to pivot the holder 55 about the live pivots 90and thus pivot the spacer 10 relative to the delivery device 80. Abracket 56 may be formed at the end of the first shaft 81 for attachmentto the link 54.

In one embodiment, spacer 10 and delivery device 80 are positioned in afirst orientation as illustrated in FIG. 11. A longitudinal axis 300 ofthe spacer 10 forms an acute angle α with a longitudinal axis 200 of thedelivery device 80. This orientation provides for the footprint of thespacer 10 to be reduced during the insertion procedure such that thespacer 10 is positioned within the patient in a minimally invasivemanner. In one embodiment, the longitudinal axis 300 is substantiallyaligned with the longitudinal axis 200 (i.e., angle α is less than about10 degrees).

Once positioned between the vertebral members, spacer 10 is pivotedrelative to the delivery device 80 as illustrated in FIG. 15. The spacer10 is pivoted relative to the delivery device 80 such that angle α isincreased from the first orientation. In one embodiment, angle α isincreased to between about 75 and 110 degrees. In one embodiment,articulation is caused by moving the first shaft 81 relative to thesecond shaft 82. The holder 55 is connected to the second shaft 82 andrelative movement of the first shaft 81 causes the holder 55 to pivotabout pivots 90. The amount of relative movement of the shafts 81, 82translates to the amount of articulation or angle of the spacer 10relative to the delivery device 80.

The spacer 10 may be articulated relative to the delivery device 80 in avariety of different methods. In one embodiment illustrated in FIGS. 16and 17, a member 299 is axially aligned with a proximal end of the shaft82. In one embodiment, member 299 includes a threaded section and anon-threaded section. Proximal end of the shaft 81 includes extensions131 positioned against the non-threaded section. The shaft 81 movesaxially relative to the member 299. A drive sleeve 130 is connected tothe shaft 81 and is positioned over the member 299. Drive sleeve 130includes internally-positioned threads that mate with the threadedsection of member 299. Rotation of the drive sleeve 130 causes axialmovement of the shaft 81 relative to the shaft 82 thus pivoting thespacer 10. In one embodiment, drive sleeve 130 is attached to the firstshaft 81 by a slip ring.

Once properly articulated and positioned between the vertebral members,spacer 10 is deployed from the closed orientation towards the openorientation. A deploying means is positioned within the delivery device80 to deploy the spacer 10. In one embodiment, a cam 84 is positionedwithin delivery device and includes a distal end adjacent to the end ofthe delivery device 80, and a proximal end positioned at the deployer 7.In one embodiment, cam 84 is positioned within the second shaft 82 andis axially moved through the delivery device 80.

Movement of the cam 84 is illustrated in FIGS. 18 and 19. In the closedorientation, delivery device 80 is attached to the spacer 10 with thecam 84 in a first position and third member 40 positioned at theproximal end of the spacer 10. Cam 84 is axially moved within thedelivery device 80 to move the third member 40 towards the distal end ofthe spacer 10. A distal end of the cam 84 contacts a proximal end of thethird member 40 to push the third member 40 and deploy the spacer 10.The amount of axial movement of the cam 84 controls the amount of spacerdeployment. Axial movement of the cam 84 from the first orientation tothe second orientation causes the third member 40 to move relative tothe first member 20 causing the angled sections to contact and increasethe spacer height. The amount of movement of the cam 84 controls theamount of increase of spacer height. The cam 84 is operatively connectedto the third member 40 meaning it may be attached to the third member40, or unattached but placed in contact with the third member 40 duringactuation.

FIG. 22 illustrates another embodiment of the third member 40. Thisembodiment is similar to the previous embodiment illustrated in FIG. 4,with the addition of a lug 140 on a proximal end. Lug 140 includes acontact surface 142 that is contacted to the distal end of the cam 84during the deployment. FIG. 23 illustrates another embodiment of the cam184 having a distal end 185 that contacts the contact surface 142. Inone embodiment, the distal end 185 is substantially perpendicular withthe side edges. The contact surface 142 and distal end 185 are shapedsuch that a contact angle E formed between the two surfaces is maintainas small as possible during the deployment. Additionally, there is agreater amount of contact between the distal end 185 and contact surface142 during deployment. Cam 184 may have a variety of configurations,including a pushrod that extends along all or a section of the deliverydevice 80 and includes a distal end 185 that contacts the spacer todeploy it to the expanded size.

In an embodiment having only first and second members (i.e., no thirdmember), the first member has angled surfaces that contact a secondmember having angled surfaces. Cam 84 is positioned to contact one ofthe first or second members and provide relative movement fordeployment.

FIGS. 6 and 7 illustrate the movement of the third member 40 caused bythe cam 84. In one embodiment, third member 40 is positioned proximallywithin the spacer 10 as illustrated in FIG. 6. Movement of the cam 84moves the third member 40 distally as illustrated in FIG. 7 causing thespacer 10 to deploy. One manner of reducing the spacer 10 is by movingthe cam 84 proximally and pulling the third member 40.

FIG. 1 illustrates one embodiment of the delivery device 80 and deployer7. Various types of deployers can be applied to the delivery device 80to expand the spacer 10. The deployer may be positioned adjacent to thespacer 10, or positioned distant from the spacer 10 to be outside thepatient. Previously filed U.S. patent application Ser. No. 10/178,960entitled Minimally Invasive Expanding Spacer and Method, filed Jun. 25,2002 and assigned to the same entity as the present application, nowU.S. Pat. No. 7,087,055, discloses deployers and structures fordeploying the spacer towards the open orientation and is hereinincorporated by reference in its entirety.

In one embodiment, deployer 7 is attached to a proximal end of thedelivery device 80. Deployer 7 is attached to a lock 89 that is attachedto the cam 84. Deployer 7 provides axially movement of the cam 84through the delivery device 80. In one embodiment, knob 302 includes athreaded connection to a contact member. Rotation of the knob causes thecontact member to move outward relative to the knob 302. When thedeployer 7 is mounted to the delivery device 80, contact member abutsagainst the proximal end of the lock 89. Rotation of the knob 302 causesthe contact member to axially move the lock 89 and thus the cam 84.

In one embodiment, the amount of axial movement of the cam 84 iscontrolled. FIG. 20 illustrates one embodiment with the lock 89positioned an axial distance from the shaft 82 (i.e., FIG. 20illustrates the cam 84 in a retracted position). Movement of thedeployer 7 causes the lock 89 and cam 84 to move axially relative to theshaft 82. The amount of movement is limited as the distal end of thelock 89 contacts the proximal edge of the shaft 82. Various other typesof deploying mechanisms may be used for axially moving the cam 84 anddeploying the spacer 10.

Delivery device 80 may be attached to the spacer 10 in a variety ofdifferent manners. In one embodiment, spacer 10 is connected throughmovable live pivots 90 that extend through apertures 37. The live pivots90 connect the spacer 10 to the delivery device 80. In a detachedorientation, live pivots 90 are moved below the apertures 57 and thedelivery device 80 is detached from the spacer 10. One embodiment isillustrated with FIG. 21. Cam 84 extends through the delivery device 80and has an extended configuration with a first dimension larger than asecond dimension. Pivots 90 are positioned adjacent to the cam 84. Inthe attached orientation, cam 90 is orientated with the larger dimensionaligned relative to the pivots 90. The pivots 90 contact the cam 84 andextend outward through the apertures 57. In the detached orientation,cam 84 is rotated such that the smaller dimension contacts the pivots90. The pivots 90 retract and the top edge 99 moving away from theapertures 37. In one embodiment, cam 84 is structured with the largerand smaller dimensions being separated by about 90° (i.e., rotation ofthe cam 84 about 90° results in movement between the attached anddetached orientation). In one embodiment, pivots 90 include a roundedsurface 91 to facilitate detachment of the spacer 10. In one embodiment,cam 84 is retracted prior to the spacer 10 being detached from thedelivery device 80. Embodiments of an attachment, delivery, anddeployment device and method are disclosed in U.S. patent applicationSer. No. 10/202,918, now U.S. Pat. No. 7,572,276, entitled MinimallyInvasive Instruments and Methods for Inserting Implants, filed on Jul.25, 2002 and assigned to the same entity as the present application,herein incorporated by reference in its entirety.

In one embodiment, cam 84 extends through a section of the deliverydevice 80 and is accessed towards a proximal end of the delivery device80. A physician using the apparatus 9 rotates the cam 84 from a pointexterior to the patient for detaching the spacer 10 from the deliverydevice 80. One embodiment is illustrated in FIG. 20 with cam 84extending through the shaft 82 and being attached to the lock 89. Thelock 89 is fixedly attached to the cam 84 with rotation of the lock 89causing rotation of the cam 84. A proximal end of the shaft 82 and adistal end of the lock 89 have corresponding fingers 113 that controlthe amount of cam rotation. Rotation of the lock 89 relative to theshaft 82 is limited to a predetermined range because the fingers 113will contact and prevent further rotation. In one embodiment, fingers113 are positioned to limit rotation to about 90°. Previously filed U.S.patent application Ser. No. 10/178,960, which has already beenincorporated by reference in its entirety, discloses several differenttypes of delivery devices and structures for controlling the spacer.

FIGS. 24 and 25 illustrate another embodiment of the detachment deviceto disconnect the spacer 10 from the delivery device 80. The deliverydevice 80 includes a drive sleeve 149 with a tube sleeve 150 at a distalend. A release sleeve 153 having a predetermined width is slidablypositioned over the tube sleeve 150. A pushrod 184 extends within thetube sleeve 150 and includes a distal end 185 that deploys the spacer10. Extensions 151 are positioned towards the distal end of the tubesleeve 150 and mount within apertures 157 of a holder 155 and apertures37 within the spacer 10. The spacer 10 pivots about the extensions 151as it is connected to the delivery device 80. A link 154 extends betweenthe holder 155 and drive sleeve 149. Relative movement of the drivesleeve 149 relative to the tube sleeve 150 causes the spacer to pivot.

As illustrated in FIG. 26, tube sleeve 150 includes a distal end havingone or two ramped surfaces 152. The ramped surfaces 152 graduallyincrease along the tube sleeve 150 to a maximum height at a pointadjacent to the extensions 151. A slot 159 is formed on the distal endof the tube sleeve 150 between the ramped surfaces 152. The slot 159 hasa width w when the extensions 151 are mounted to the spacer 10.

The release sleeve 153 is slidably mounted on the tube sleeve 150. Therelease sleeve 153 has a predetermined width that is greater than thewidth of a first section 158 of the tube sleeve 150 away from the rampedsurfaces 152, but less than a width of the ramped surfaces 152.

FIGS. 27 and 28 illustrate the disconnecting of the delivery device 80from the spacer 10. In FIG. 27, the spacer 10 is connected to thedelivery device 80 as the extensions 151 are positioned through theholder 155 and spacer 10. The release sleeve 153 is positioned away fromthe extensions on a first section 158 of the tube sleeve 152. FIG. 28illustrates the spacer 10 being disconnected from the delivery device80. Release sleeve 153 has been distally moved in the direction of arrowx along the ramped surfaces 152 of the tube sleeve 150. This causes theramped surfaces 152 to be forced inward thus reducing the width w.Extensions 151 mounted to the distal end of the tube sleeve 150 likewiseare forced inward and detach from the spacer 10. At this point, thespacer 10 can be removed from the delivery device 80. The holder 155remains attached to the delivery device 80 and is removed leaving onlythe spacer 10 within the patient.

In one embodiment, the pushrod 184 extends through the slot 159 in thetube sleeve 150 and prevents the spacer 10 from being disconnected.While the pushrod 184 is within the slot 159, the ramped surfaces 152are prevented from being forced together and therefore the extensions151 remain within the spacer 10. Once the pushrod 184 is removed (i.e.,moved in a “-x” direction), the ramped surfaces 152 can be forcedtogether with the width w reduced to remove the extensions 151 from thespacer 10. In another embodiment, there is adequate clearance betweenthe pushrod 184 and the ramped surfaces to allow the width w of theopening 159 to be reduced and the spacer detached. In one embodiment, anattachment may extend from the release sleeve 153 towards the proximalend of the delivery device 80 to allow a physician to release the spacer10 from a remote position.

In another embodiment, delivery device 80 may be attached to the spacer10 via a shearable pin that is designed to fail once the spacer 10 isdeployed. Once the pin is sheared, the delivery device 80 is removedfrom the spacer 10. In another embodiment, delivery device 80 isattached to the spacer 10 by threads. Rotation of the delivery device 80relative to the spacer 10 causes the spacer to dislocate from the device80. In another embodiment, delivery device 80 and spacer 10 are equippedwith a half turn locking system such that rotation of the deliverydevice 80 relative to the spacer 10 causes dislocation.

The delivery device 80 may remain attached to the spacer 10 or may bedetached from the spacer during use. Removing the delivery device 80 maybe necessary to provide additional operating space for the physicianduring the procedure as the delivery device 80 may interfere with otherequipment, or the vision if it were left attached to the spacer 10. Inthis usage, the delivery device 80 may further be reattached to thespacer 10 for removal from the patient at the end of the procedure. Inanother usage, the delivery device 80 is removed and the spacer 10remains permanently within the patient.

In one embodiment, cam 84 extends through the shaft 82 and includes aproximal end mounted to the lock mechanism 89. In one embodiment, cam 84is not connected to a lock. In one embodiment, cam 84 is axially movableand rotatable within the shaft 82. In one embodiment, the second shaft82 is mounted within the first shaft 81. In one embodiment, the firstshaft 81 is sized to slide along the exterior of the second shaft 82. Inone embodiment, the second shaft 82 is axially stationary during thearticulating and deploying processes. In one embodiment, member 200 isstationary during the articulating process.

The term vertebral member is used generally to describe the vertebralgeometry comprising the vertebral body, pedicles, lamina, and processes.The spacer 10 may be sized and shaped, and have adequate strengthrequirements to be used within the different regions of the vertebraincluding the cervical, thoracic, and lumbar regions. In one embodiment,spacer 10 has a load capacity of about 2000 lbf.

The spacer may be positioned within the disc space between adjacentvertebras. Contact surfaces 21, 31 contact the end plates of thevertebra to space the vertebra as necessary. The spacer 10 may beinserted posteriorly, anteriorily, or laterally into the patient.

The contact surfaces 21, 31 may be porous to allow bone ingrowth intothe spacer 10. One or both contact surfaces 21, 31 may include one ormore apertures. Bone growth material is positioned within the aperturesto accommodate bone growth through the entire implant. The bone growthmaterial may include a sponge, matrix, and/or other carrier impregnatedwith a protein such as bone morphogenic protein (BMP), LIMmineralization protein (LMP), etc.

In one embodiment, the spacer 10 is deployed using a pair of levers. Inone embodiment, the spacer is deployed with an instrument having a pairof offset arms similar to a scissors.

The present invention may be carried out in other specific ways thanthose herein set forth without departing from the scope and essentialcharacteristics of the invention. In one embodiment, spacer 10 anddelivery device 80 are constructed of stainless steel. In oneembodiment, support sections are positioned distally of the angledsurfaces. In one embodiment, the cam 184, 84 is a pushrod. In oneembodiment the biasing member 108 is a coil spring. In one embodiment,when the spacer 10 is in the open orientation the angled surfaces of themembers are in contact. In one embodiment, second member 30 does notinclude sidewalls 33, and the third member 40 has a width smaller thanor equal to the width of the second member 30. In one embodiment, spacer10 is constructed of titanium. In one embodiment, the apertures 37 inthe spacer are about 3.5 mm in diameter. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

1-20. (canceled)
 21. A method of spacing vertebral members comprisingthe steps of: placing a spacer between the vertebral members, the spacerbeing in a first orientation and having opposing exterior sidesdistanced at a first height; and moving a first ramped surface withinthe spacer relative to a second ramped surface within the spacer to asecond orientation and separating the opposing exterior sides to asecond height that is greater than the first height.
 22. A method asrecited in claim 21, further comprising contacting a first platformsurface in contact with a second platform surface in the secondorientation.
 23. A method as recited in claim 21, further comprisingmoving the first ramped surface from a proximal end of the spacer in thefirst orientation to a distal end of the spacer in the secondorientation.
 24. A method as recited in claim 21, further comprisingdetaching a delivery device from the spacer by moving a release sleevealong the delivery device and forcing opposing ramped surfaces inward toretract extensions inward to dismount from the spacer.
 25. A method asrecited in claim 21, wherein the step of moving the first ramped surfacewithin the spacer relative to the second ramped surface comprisespushing one of the first ramped surfaces or the second ramped surfaceswith a cam.
 26. A method as recited in claim 21, further comprisingdetaching a delivery device from the spacer by rotating a cam within thedelivery device and retracting live pivots inward.
 27. A method asrecited in claim 21, wherein placing the spacer comprises positioningthe spacer between the vertebral members with the first ramped surfacedisengaged from the second ramped surface.
 28. A method as recited inclaim 21, wherein: the spacer comprises a first member comprising thefirst ramped surface and a second member comprising the second rampedsurface; and moving the first ramped surface comprises applying apushing force to the first member.
 29. A method as recited in claim 28,wherein the step of applying the pushing force to the first membercomprises contacting the first member with a cam that extends along adelivery device.
 30. A method as recited in claim 28, wherein moving thespacer to the second orientation comprises moving the first member froma proximal position towards a distal position and engaging the firstramped surface with the second ramped surface.
 31. A method as recitedin claim 28, wherein: the first and second members are positioned in avertically overlapping arrangement with interior sides of each of thefirst and second members facing together and a sidewall of the firstmember being in a horizontally overlapping arrangement with the secondmember such that the first and second members define a device length;and the device length remains constant as the spacer is moved from thefirst orientation to the second orientation.
 32. A method of spacingvertebral members comprising the steps of: attaching a spacer to adelivery device; manipulating the delivery device and positioning thespacer between the vertebral members; deploying a pushrod through thedelivery device with a distal end of the pushrod contacting a firstmember of the spacer; moving the first member of the spacer from aproximal position towards a distal position; and engaging a first rampedsurface on the first member with a second ramped surface on a secondmember of the spacer as the first member moves from the proximalposition towards a distal position and increasing a width of the spacer.33. A method as recited in claim 32, wherein the step of attaching aspacer to the delivery device comprises attaching pivots on the deliverydevice to apertures within the spacer.
 34. A method as recited in claim33, further comprising detaching the pivots from the apertures byrotating the push rod within the delivery device such that a smallersection of the push rod is aligned with the pivots and the pivotsretract within the apertures.
 35. A method as recited in claim 32,wherein the step of attaching a spacer to the delivery device comprisesattaching extensions on a distal end of a first tube to apertures withinthe spacer.
 36. A method as recited in claim 35, further comprisingdetaching the extensions from the apertures by moving a release sleevealong the first tube and squeezing first and second arms together so asto reduce a distance between the extensions.
 37. A method as recited inclaim 32, wherein: the first and second members are positioned in avertically overlapping arrangement with interior sides of each of thefirst and second members facing together and a sidewall of the firstmember being in a horizontally overlapping arrangement with the secondmember such that the first and second members define a device length;and the device length remains constant as the first member is moved fromthe proximal position to the distal position.
 38. A method of spacingvertebral members comprising the steps of: positioning a spacer betweenthe vertebral members with the spacer in a closed orientation such thata third member is positioned between a first member and a second member;pushing the third member from a proximal position towards a distalposition; and engaging a first ramped surface on the first member with asecond ramped surface on the third member as the third member moves fromthe proximal position towards the distal position.
 39. A method asrecited in claim 38, wherein: when the spacer is in the closedorientation, the first ramped surface is disengaged from the secondramped surface and the spacer has a first height defined by a distancebetween a first outermost contact surface of the first member and anopposite second outermost contact surface of the second member; and whenthe first ramped surface engages the second ramped surface, the spacerhas a second height between the first outermost contact surface and thesecond outermost contact surface, the second height being greater thanthe first height.
 40. A method as recited in claim 39, wherein a maximumlength of the spacer remains constant when the spacer is in the closedorientation and when the first ramped surface engages the second rampedsurface.